1. Field of the Invention
This invention pertains to plasticizers for pyrotechnic materials and, more specifically, to energetic plasticizers of reduced volatility for solid propellant systems.
2. Description of the Prior Art
Solid propellants are formulated from an oxidizer and fuel together with suitable binders and plasticizers to impart physical integrity. Most highly energetic systems utilize binders and plasticizers containing energetic groups such as nitro (--NO.sub.2), fluorodinitro (FC(NO.sub.2).sub.2 --), difluoroamine (--NF.sub.2), and many others.
Utilization of azido plasticizers has become a reality during the last several years. These azido plasticizers impart additional energy to propellants since each azido group present adds approximately 85 kcal/mole of energy to the system. It follows that utilization of an azido polymer would impart additional energy to the system. Unfortunately, the few azido polymers synthesized to date are not functionally terminated which is a necessity for good propellant castability and physical properties.
One functionally terminated azido polymer is taught by Delzenne et al, U.S. Pat. No. 3,453,108. Another is the hydroxy-terminated aliphatic polyether having directly pendant alkyl azide groups of U.S. Pat. No. 4,268,450. In that this plasticizer has a completely different structural formula, completely different chemical and physical properties, the teachings of the prior art would not render obvious the presently claimed alkyl, azido, nitro ethers.